G A Vishnyakova

Two-stage laser cooling and optical trapping of thulium atoms

We propose to use the magnetic-dipole transition at λ = 1.14 μm coupling two ground state fine-structure components of thulium (Tm), as a clock transition in optical clocks. We have demonstrated first stage laser cooling of Tm atoms down to a temperature of 25 μK using a strong transition at λ = 410.6 nm and we have also shown preliminary results for second stage cooling using a weaker transition at λ = 530.7 nm (natural linewidth γG = 350 kHz). Laser cooled atoms have been trapped in an optical dipole trap and in a 1D optical lattice operating near 532 nm.

Coherent population trapping resonances in the problem of quantum filtering of light pulses

The conditions necessary to implement a single-photon pulse source using quantum filtering based on the coherent population trapping phenomenon in N-systems of atomic levels are determined. The dependences of dark resonance characteristics on laser field intensities are experimentally measured in Rb vapor. These dependences define optimum intensity ratios and pulse durations of used laser beams, at which the system can efficiently operate as a single-photon quantum filter.

Short-haul fibre-optic communication link with a phase noise compensation system for optical frequency signal transmission

A 5-m-long fibre link with a phase noise compensation system for optical frequency signal transmission at a wavelength of 1.14 μm is demonstrated. The stability of the noise compensation system in the presence of harmonic mechanical perturbations is assessed and the relative transmitted signal frequency instability is shown to be 3.8 × 10−15 at an averaging time of 1 s and 3.5 × 10−20 over 850 s.